High affinity [3H]imipramine and [3H]paroxetine binding sites in suicide brains.
Specific binding of [3H]imipramine and [3H]paroxetine was simultaneously examined in human brains (frontal cortex, temporal cortex, cingulate cortex, hypothalamus, hippocampus and amygdala) from 11 controls and 11 depressed suicide victims. A single saturable high affinity site was obtained for both radioligands. Age was not related to significant changes in [3H]imipramine and [3H]paroxetine binding parameters, which indicates the stability of the brain serotonergic system with increasing age. A major finding of the present study concerns the existence of a significant decrease in the maximum number (Bmax) of [3H]imipramine binding sites in hippocampus from depressed suicides as compared with the control group, without changes in the binding affinity (Kd). In contrast, when [3H]paroxetine was used as radioligand, no changes in either Bmax or Kd were detected in any of the brain regions studied. These findings suggest that [3H]imipramine may be a better marker than [3H]paroxetine when alterations in the presynaptic serotonergic uptake site are to be detected.
Rosel
P
P
Hormone Unit (Biochemistry Department), Hospital Princeps D'Espanya, Barcelona, Spain.
Arranz
B
B
Vallejo
J
J
Oros
M
M
Menchón
J M
JM
Alvarez
P
P
Navarro
M A
MA
D000293:Adolescent; D000328:Adult; D000368:Aged; D001665:Binding Sites; D001921:Brain / Q000378:metabolism*; D003863:Depression / Q000378:metabolism*; D005260:Female; D006801:Humans; D007099:Imipramine / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D017374:Paroxetine / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism; D017367:Selective Serotonin Reuptake Inhibitors / Q000378:metabolism*; D013405:Suicide
D007099:Imipramine; D017374:Paroxetine; D012701:Serotonin; D017367:Selective Serotonin Reuptake Inhibitors